The current mapping of smp_processor_id() to a CPU processing Tasks-RCU callbacks makes some assumptions about layout. This commit therefore adds a WARN_ON() to check these assumptions.
Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/tasks.h | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index b6fcf744af75d..d473846a572aa 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -355,6 +355,7 @@ static void call_rcu_tasks_generic(struct rcu_head *rhp, rcu_callback_t func, rcu_read_lock(); ideal_cpu = smp_processor_id() >> READ_ONCE(rtp->percpu_enqueue_shift); chosen_cpu = cpumask_next(ideal_cpu - 1, cpu_possible_mask); + WARN_ON_ONCE(chosen_cpu >= nr_cpu_ids); rtpcp = per_cpu_ptr(rtp->rtpcpu, chosen_cpu); if (!raw_spin_trylock_rcu_node(rtpcp)) { // irqs already disabled. raw_spin_lock_rcu_node(rtpcp); // irqs already disabled. -- 2.40.1
